Automatic system for burning fuel under boilers



Jne 3, 1930. E. sKlLLMAN Er AL AUTOMATIC SYSTEM FOR BURNING FUEL' UNDER 'BOILERS Filed 00.11. l3. 1924 PRESSURE p Patented June 3, 1930 UNITED STATES PATENT OFFICE EDWARD SKILLMAN AND GUY HARMON, BARTLESVILLE, OKLAHOMA, ASSIGNORS T DOHERTY RESEARCH COMPANY, OF NEW YORK, N. Y.,.A CORPORATION OF DELA- WARE AUTOMATIC SYSTEM FOR BURNING FUEL UNDER IBOILERS Application filed october 13,1924. serial no. 743,367.

The present invention relates to automatic systems for burning fuel underboilers.V

It-has beenpropo'sed to burn either li'quid or gaseous` fuels under boilers and to regulate the intensity of the lire inversely as the steam pressure, or lroughly so, 'so'that the process of raising the steam should require a minimumV of attention. Systems `of the type just referred to have been installed to some 3o extent, but their expense has limited their application. Moreover, such systems have required more attention than desirable. No system has been introduced heretofore Which has met the practical requirements as to l5 burning Yliquid fuel automatically 'Well enough Vto be installed in individual boilers and particularly inthe installations operating under severe conditions such as obtain in the oil fields or other places Where boilers are Z0 moved from place to place at relatively short intervals. i

It is onel of the objects of the present invention to provide'a simple and reliable automatic fuel firing system and one suiiiciently cheap and compact to permit its vWide-use.

A second object ofthe present `invention is to provide a reliable automatic oil burning equipment capable of being readily moved from place to place and set up in Vnew loca-- tions. v Y

` The novel features of the present invention are pointed out lWith particularity in the appended claims. The invention itself, together with other objects and advantages,

will best be understood from the following description taken in connection with the accompanyingdrawings, in which: A

Fig. 1 is an elevation partly insection, of a locomotive type boiler equipped with` an automatic oilburning system accordingvto the present invention.; f f

Fig. 2 is an elevation on a larger scale and looking in the same direction'as Fig. 1 of the-burner` and draft controlling motor and associated parts according to the present invention. In Fig. 2 the draft and fuel controlling kmoto-r is shown in section for pur# poses of illustration. Y Fig, 3 is an elevation of the apparatus illustrated in Fig. :2 When looking in the direction indicated as 3 3 in Fig. 2.

Fig. l is a section of the fuel and steam controlling valve according to the present invention taken on line ,l-Of Fig. 5, the valve being shown in position giving minimum burner flame. f F ig. 5 is a section of the fuel and steam valve taken on the line 5,5 of Fig. 4.

Fig. 6 is a view similar to Fig.4, but showinggthe fuel valve in position for maximum burner "flame, Fig. 7 is an end View of the plug of the fuel and steam valve.

In the drawing 10 indicates a boiler having a lire box 12, boiler 10 being equipped .with

a fuel firing and steam regulating system `according to the present invention. Boiler 10 has also a steam-dome- 14 from which steam for use is led off through steam line 16. Connected to the steam line 16 .is a boilerregulator 18 having a vacuum line 2O connected thereto. Regulator 18 is ofa knowntype adapted to create ya vacuum or subatmospheric pressure on line 20 whichk is of greater intensity, or in -other Words of less absolute pressure, as the steam boiler pressure in-' creases.- The Vconstruction of the regulator 18 'forms no part ofthe present invention, and is not claimed herein, but 1s preferably of the construction disclosed in the prior application of James P. Fisher, Serial No.

723,842, filed July 2, `1924, for boiler govf ernor.

The lire box 12is illustrated as being. setover an auxiliary combustion chamber or furnace 22 Which may be ofsuitable briclrjor fire clay construction to withstand thev oil flame. One Wall of the furnace 22 is illus` trated as having an aperture 2 4 therein looking toward the smoke box end of boiler-,10. Inserted into `the aperture 24 is a box 26 act7 ing asv a combined burner support and air in.- letflue. An oil burner'28 is mounted Within the box 26 adjacentthe end of box 26 prof jecting into the Wall of furnace 22. Burner 28 is illustrated as afixed to a steam pipe 32 and an oil pipe 30. Pipes 30 and 32 are run parallel to one of the vertical sidewalls of the box-26 on the outside of the box, passing through a door Z7 forming Part of. the `Side wall near its longitudinal center and thence running within the box to the burner 28. Near the end of the box 26 removed from the furnace 22 is mounted a combined steam and oil va ve mechanism 34. A iiange 38 formed on the mechanism 34 is affixed to side of box 26 so as to cover an apertui'e in the side of the box. Rotatably mounted within the body of the mechanism 34 is a valve plug 40 having suitable valve ways therein for permitting the flow of both the oil and steam and for regulating such flow. The valve ways through plug 4() are of similar shape, the way for the steam being illustrated at 42 in Figs. 4 and 6 and the way for oil being illustrated at 43 in Fig. 5. The mechanism 34 comprises two bosses 46 and 48 for the oil and steamrespectively. The pipes and 32 for the oil and steam are each interrupted at the valve casingl 34 andk connected to the bossesV 46 and 48; Oil pipe 30 is connected to a source of oil under pressure, preferably at nearly constant pressure, and. pipe 32 is connectedto steam dome 14; valves 3l and 33 f being provided in the two lines.

According to the present invention, means are provided whereby the valve is automaticallythrown from the position giving the maximumflowv of oil vand steam and consequently the maximum flame to that giving minimum fiow of oil and steam and Consequently the. minimum fiame. it is desired,l however, accordingto the present invention that the flame not be entirely extinguished'at any timeand for this reason the opening 42 is made in the form illustrated and in which i there is asmall opening 44 permittingpassage, of fluid even when the plug 40 has been turned to its position of minimum fiow.

The air for maintaining the flame in fur-- nace 22 is introduced through the box 26 on which burner 28 is mount-ed. The valve plug 40 projects through the wall of box 26 as illustrated in Figs. 3 and 5, and the end of the plug 40 within the box 26 is slotted as illustrated' at 50 (Figs. 5 and 7) to receive the edge ofadamper 52. Damper 52 is mounted to swing on a horizontal axis within the boxv 26A` one edge of the damper being -fixed in the slot 50 so that the plug 40 serves as one pivot for damper 52, the other pivot being illustrated as projecting through the wall of box 26 -at 54, opposite-the plug 40.

The air for maintaining the. flame in the boiler furnace is introduced through the boxV 26in which` the burner 28 is mounted. The amount of air used for combustion is carefully regulated so astosupply the air in accordancewiththe volume of oil to be burned. The control ofair -is maintained by means of they damper 52 which ismounted within the box 26.v Y

Valve plug 40. and damper 52 are operated simultaneously` and automatically according to. the present invention bymeans of a Vmotor 56 mounted on top of box 26 and operated by the vacuum pressure developed by the boiler regulator 18. Asis clearly illustrated in Figs. 2 and 3, the motor 56 comprises a closed casing split along the central horizontal line at 58 to receive a diaphragm 60.which is clamped between the two Vportions of the motor casing. Fixed to diaphragm 60 within the casing of the motor 56 are weights The diaphragm 60 is adapted tomove up and down carrying with it the weights 62, dcpending uponthe differences in pressure on its opposite sides. The vacuum line 20 of the boiler regulator is` connected into the casing of motor 56 above the diaphragm 60, the lower faceof the diaphragm being exposed Ito atmospheric pressure admitted intol the casing ofthe motor through aperture 64 illustrated as being` in the center of the bottom of the casing. A piston lr-od 66 is connectedf to diaphragm 60 and weights 62 as illustrated andv extends through the aperture 64 andthence downwardly through the top of the box 26, the lower end of the rod 66 being'pivotally connected to a bracket 68 fixed to one face of the damper 52 (Figs. 2 and 3). Damper 52 is slotted as illustrated at 70 (Fig. 3) so that the damper may swing on its axis without interference from the rod 66. Also, a set screw 72 is threaded into the top of?the.casing of motory 56 and can be adj ustedfto contact with the upper weight 62 so as t-o hold the valve plug, 40 and the damper 52 intheposition forl minimum fiame. The weights `62 are positionedvonthe rod 66 so that the lower of the weights 62 shall rest on the bottomof the casing. of motor; 56 when the damper 52 andwalveplug40 are in theposition for maximum flame.

It will 'be seen from the foregoing` that as the diaphragm 60 is moved up and down by changes in pressureon its opposite faces, the rod 66 will turn the damper 52 and the valve plu40. The .parts-are'so arrangedthat when the diaphragm 60 is in its uppermost position, the damper 52 fcuts down the flow of air through box` 26A to a; minimum, and at the same time the plu-g 40 cuts down the flowV of oil and steam-also to a minimum. When the diaphragm 60 and weights 62 are in their lowermost position, the dampe152 is. substantially horizontal tofpermit the maximum flow of air through box 26 and the flow of oil and steam is such as to produce a maximum fiame. This maximum flame. for any given boiler` and furnace conditions is adjusted in the ordinary manner by adjusting the oil valve 31 and steam valve 33"permitting the greatest oil' flow possible under the given boi-ler conditions without causing incomplete combustion.

The-diaphragm 60 and weights-62 aresubjectronly tothe-action ofgravity and to the pressures as previouslyV described. Consequently if` the difference theV pressure 0n the two sides of diagram is sufficient to lift the weights 62 they will move upwardly without intermission until the parts produce the minimum flame conditions as before de-` scribed. As soon now as the pressure conditions of diaphragm 60 are insufficient to support the weights 62, the weights will move down without intermission and the parts will assume the position giving maximum flame as above described. This action will be slightly retarded, to be sure, by the effects of friction in the valve mechanism 34 and on the pivot 54, but when the weights once begin to move they will travel uninterruptedly from thermaximum position to the minimum or the reverse without interruption; i

As before mentioned, governor 18 produces a maximum vacuum on the line 20, and con? sequently in the upper part of the motor'v under conditions Vof maximum ysteam pressure. Therefore in the operationy of the apparatus, the parts being assumed as giving the maximum flame, as soon as the demand `for steam permits, the steam pressure will rise to a predetermined maximum at which point the motor 56 will shift the valve and damper to give a minimum flame. TWhen now the use of steam or the effect of heat losses has reduced the steam pressure to a predetemined minimum, the motor ,56 will throw in a maximum flame again.

It will be observed that no attempt is made to graduate the intensity of the flamerin accordance with the demand for steam or in accordance with the steam lpressure exceptl as determined bythe desired maximum and minimum flame conditions. Such graduated regulation, although often attempted in the past, introduces unnecessary complications in the apparatus, and at leastA as good fuel economy can be obtained without such features. As the conditions of the maximum and minimum flames lare the only ones under which the apparatus operates for any appre.

ciable time, it is unnecessary to adjust closely the relation between air., steam andthe oil flow for any other conditions, but the passages in the plug 40 are lso proportioned and valves 3l and 33 in theoil and steam lines respectively so adjusted and Vthedamper opening so regulatedthat the fuel isrburned' to best advantage both at maximum flame` and minimum flame.

Having thus described 'our invention, we claim:

l. The combination of a portable conduit adapted to supply air for combustion to the fire-box of a furnace, a casing containing a weighted motor element, avdamper for controlling air How through said conduit, a fuel valve, a steam valve, said fuel and steam valves having movable elements mountedon the axis of said damper and connected to turn therewith, operating connections between said motor element and said axis, a fuel burner, vandV fuel .and steam pipes connecting said'valves and, said burner. y

-2. The combination of a conduit adapted to supply air for combustion to the fire-box of a furnace, a moto-r element, a damper for controlling the How of air through said conduit, a fuel valve, a steam valve,.each ofsaid valves having-a passageway at right angles to that of the other and having its movable element mounted on the same axis as said damper and connectedy to turn therewith,

yoperating connections between said motor element and said axis, a fuel burner, and fuel and steam pipes connecting said valves and said burner. f

yof a furnace, a motor element, a damper pivoted on a rotatable` axis, a lug fixed to one side of said damper near said axis,a rigid connec-` vmotor element therein, a damper pivotedy on a rotatable axis for controlling air supply through said conduit, a projectionY fixed to one sideof said damper near said axis, and a connection between said motor element,l and said projection.

5. The combination as set forth in claim 4 together with a fuel valve fixed to the exterior of the conduit, a steam valve fixed to the exterior of said conduit, said valves having their movable elements mounted on the same axis assaid damper and connected to turn therewith, a fuel burner, and fuel and steam pipes connecting said valves andfsaid burner.

6. The combination of a portable conduit adapted to supply airfor combustion to the firebox of a furnace, a casing containing a weighted motor element and fixed to said conduit, a damper within said conduit, a fuel valve fixed to the exterior of said conduit, a

3. The combination of arconduit adapted to vsupply air for combustion to the fire-box steamvalve fixed to the exterior of said cony duit, each of said valves having a passagev way at right angles to that of the other and thevalves having their movable elements connected and mounted to turn on the same axis, operating connections between said Firebox 0:1? a furnace, a damper mountedl On a horizontal axis andr Within said Conduit, an offset xed to said damper near saidv axis, a Casingmounted' on top of said conduit and containing" a Weighted flexible diaphragm and a connection between said diaphragm and said offset, saidv easing and conduit being apertured to receive said connection.

In testimony whereof, We affix our signatures.

EDY/JARD SKILLMAN. GUY HAR-MON. 

